My favourite laundromat is Durham's Old Cenerma Launderette: a launderette which used to be a cinema and which serves coffee would be good even if it weren't a gigs venue (which is why we go there, now we have our own washing machine).

I have a happy memory from a long-ago camping holiday somewhere in France (it might have been Perpignan), lunching on the pavement terrace of a restaurant which was conveniently opposite the laundromat, keeping an eye on our laundry between courses...